Intermolecular dearomative [4 + 2] cycloaddition of naphthalenes via visible-light energy-transfer-catalysis

Abstract

The dearomative cycloaddition reaction serves as a blueprint for creating sp3-rich three-dimensional molecular topology from flat-aromatic compounds. However, severe reactivity and selectivity issues make this process arduous. Herein, we describe visible-light energy-transfer catalysis for the intermolecular dearomative [4 + 2] cycloaddition reaction of feedstock naphthalene molecules with vinyl benzenes. Tolerating a wide range of functional groups, structurally diverse 2-acyl naphthalenes and styrenes could easily be converted to a diverse range of bicyclo[2.2.2]octa-2,5-diene scaffolds in high yields and moderate endo-selectivities. The late-stage modification of the derivatives of pharmaceutical agents further demonstrated the broad potentiality of this methodology. The efficacy of the introduced methods was further highlighted by the post-synthetic diversification of the products. Furthermore, photoluminescence, electrochemical, kinetic, control experiments, and density-functional theory calculations support energy-transfer catalysis.